Idle Speed Increase
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
PMM sends a serial data request to PCM to increase idle speed. PCM adjusts idle speed by using a special program and idle speed ramp calculations to prevent driveability and safety concerns. Idle speed boost and cancel function will vary from vehicle to vehicle and from one moment to another on a vehicle because PCM responds to changes in inputs from sensors used to control powertrain.